●洛谷P2664 树上游戏
题链：
https://www.luogu.org/problemnew/show/P2664
题解：
扫描线，线段树维护区间覆盖
https://www.luogu.org/blog/ZJ75211/solution-p2664（直接看这里吧）
Do not go gentle into that good night.
Rage, rage against the dying of the light.
————Dylan Thomas
题链：
https://www.luogu.org/problemnew/show/P2664
题解：
扫描线，线段树维护区间覆盖
https://www.luogu.org/blog/ZJ75211/solution-p2664（直接看这里吧）
